The use of magnetic recording tape to store information is well known. One method of recording on such tape is to provide a read/write head that rotates rapidly as the tape is passed by it, thereby providing data track which span a portion of the width of the tape. Examples of such data tracks include helical and arcuate data tracks.
It is often desirable to be able to provide instructions on a magnetic tape that will inform a magnetic tape drive about the characteristics of a tape that has been loaded in the drive. For example, the instructions could indicate the recording density of the tape, thereby allowing the drive to properly read and/or write on the tape. The instructions could also indicate when the drive has reached the end of the tape, thereby signaling the drive to reverse the direction that it moves the tape.
Various methods have been used to provide such information on the tape. One method involves providing one or more holes near the ends of the tape. This method can be disadvantageous because it may require the use of a separate sensor to sense the holes. Another disadvantage of this method is that the holes weaken the tape, thereby increasing the likelihood that the tape will be stretched or torn in the portions around the holes. The holes can also create "print-through", which occurs when tape is wrapped around the tape hub and additional layers of tape are pressed over the holes, causing the holes to create indentations in the additional layers of tape, which may impair the read/write process. Furthermore, in current implementations of this method, the method of detecting the presence of the holes can be unreliable.